Caring for Your Irises

Here is the useful iris care checklist developed by avid iris lovers, Leon and Norma Vogel, who have a lovely garden in Murrieta, California with their irises planted among many other flowering plants.

January and February

• Fertilize again for the Spring burst of blooms.
• Check for aphids that hid all winter at base of leaves.
• Discard all dead leaves and weeds.
• Check to see if all labels are properly set by proper iris clumps.
• Keep irises watered if a dry winter.
• Foliar feed for bigger and brighter colored blossoms.

March and April

• Look for first blooms in mid-March and all through April.
• Check for aphids and white fly and spray if they are seen.
• Water regularly if a dry winter.
• Make last foliar feeding for more flowers.
• Clean weeds and dead leaves.
• Give Japanese and Louisiana iris an application of an acid food -- a camellia-type fertilizer is good.

May and June

• Continue to enjoy lots of blooms into early June.
• Check to see if all the iris labels match their name (check bloom description)..
• Cut the bloom stalk near the ground when done blooming.
• Feed heavily (one tblsp. per rhizome) with 6-20-20 or similar mix when bloom season is over.
• Check for aphids near the rhizomes, also for leaf rust.
• Keep weeds and dead leaves removed.
• Do not neglect to water enough to keep them growing, but be careful not to over-water.

July and August

• Dig clumps that are over-crowded. Divide and share rhizomes with friends.
• Dig whole beds if necessary to thin the clumps.
• Be sure to add amendments to soil such as fertilizer, peat moss, compost, gypsum and new top soil.
• Rototill the soil well and allow to stand for a week if possible before planting new iris rhizomes.
• Feed (fertilize) at least 3 times yearly. Foliar feed in between for stellar results. Irises are heavy feeders.
• Irises can remain out of ground for 3 weeks or more before replanting. Keep dug rhizomes in cool dry place for storage.
• Replant rhizomes, the top 1/4 should be showing above the soil line to prevent rot and allow them to breathe.
• Trim the roots back to an inch when replanting-- they send out all new roots within a few weeks.
• Do not neglect to water enough to keep them growing. New beds require more water.
• Reblooming irises may surprise you with flowers in July-February.

September and October

• Complete digging and replanting of your irises.
• Fertilize again. Irises grow all winter long in Southern California. This differs from colder climates where you would want your irises to go dormant in the winter.
• Plant any new iris you may have purchased. Label your irises. Be sure mark in water-proof ink.
• Keep weeds under control. Check for aphids and white fly and spray with insecticidal soap, if necessary.
• Pull off and discard all dead leaves.

November and December

• If for some reason you didn’t get all the things done, it is not too late to fertilize or plant new irises.
• Pull weeds as necessary.
• Check for aphids often particularly if the winter is mild.
• Keep the beds clean of everything except growing iris.
• If you have reblooming iris, they need extra fertilizer and water. You can have iris blooms year-round if you include “reblooming” irises.

Photo of tall bearded iris 'Solar Fire' growing in Jim and Edith Schade garden in Ramona, CA.